Eco-Friendly Zero Clearance Throat Plate

Author: Suwat Phruksawan

Date: 11 November 2005

Like most woodworkers, I always use zero clearance throat plate with my table saw for increased safety and quality of the cuts. After more than two years of use, however, the original plastic ZCTP I used started to wear out and I need a new one.

Instead of buying, I opted for building my own. But my table saw, the Ryobi BT3100, has a pretty unique throat plate design that is not very easy to duplicate. Being too lazy to go through all the troubles of making one every time I need a new plate, I came up with the idea that would make it very easy to get a fresh blank and, at the same time, reduce the wasted materials, and save the time and energy.

And this is why I called it the "Eco-Friendly Zero Clearance Throat Plate".

The key concept is to make the throat plate only for the area that matters the most--the small area just around the blade.

To do this, I made the throat plate that fits in the saw as usual from a durable material (mine is a scrap piece of maple). But instead of using it as is, I routed out a small rectangle around where saw kerf would be. And in its place, I can drop in a relatively thin, but strong piece of material like plexiglass or Lexan and screw it in. In my case, I used a clear 3/8"-thick plexiglass because I can find it easily and it looks pretty cool.

This way, the original throat plate becomes the "base" and the plexiglass or Lexan piece becomes, effectively, the real throat plate. With this design, I no longer need to work on the complicated shape every time. To make a new blank plate, I just cut a piece of plexiglass to size, drill and countersink the screw holes and drop it in.

Although the design and the shape of the throat plate presented here applies to only BT3100, the idea is still applicable to most other table saws out there in the market.

	I started by "sculpting" a piece of maple into the shape using the OEM throat plate as a guide. I routed out the areas that might interfere with the blade at the different heights and different angles. The process is pretty much trials and errors as it is probably obvious from the look of the final piece.

Once the base is done, I cut a few piece of plexiglass to fit and install it in the base. I probably put more screws than really necessary but I want to be sure that the plexiglass will not flex when I raise the blade through during the normal uses.

Although it is easy enough to make a new one as you need, I pre-cut a few more plexiglass blanks for use as spares and for the commonly used bevel angles like 45° or 60°, etc.

	To cut the slot, I used a 2x4 sacrificial fence placed over the plate to prevent any deflection during the cut. A sharp chisel will easily scrape out the "snow" that formed around the saw kerf afterward.

A few coats of polyurethane will help protect the surface of the base. A thin coat of pasted wax buffed on the final coat will also make the plate smooth for easy gliding during the cuts.

Please note that in this design, the riving knife and "guard" is not fitted. However it could be modified to include the OEM riving knife or a shop-made splitter if desired. One of simple splitters such as a thin piece of wood with the same thickness of the saw kerf inserted at the rear should work well without much of the change.